The present invention relates generally to a laser-cutting method for processing parts such as O-rings, seals, and gaskets. Particularly, the invention relates to a laser-cutting process for cutting a shaped article and trimming flashing away from the article. The article can be a polymeric material such as a rubber or elastomeric material.
There are many conventional processes used for shaping articles such as O-rings, seals, gaskets, and other machine parts. These shaping processes include molding, machining, and forging operations. Various materials, such as polymers, ceramics, and metals, can be molded into articles for different applications. However, a problem with conventional shaping processes is that the final shaped article often has rough edges and surfaces. These rough edges and surfaces may contain excess material in the form of flashing or burrs. Particularly, molding processes leave the article with parting lines and burred edges. For example, in a typical rubber injection-molding processes, rubber is forced into a mold under pressure. The mold is made from two molding members joined together. The molded article, once removed from the mold, has parting lines and excess rubber material (flashing) on its surface. The molded article must be subjected to a finishing process to remove the flashing. This finishing process is referred to as de-flashing or de-burring.
Current methods of de-flashing and de-burring excess, fringe material from a shaped article including cryogenic de-flashing, manual trimming, and mass media tumbling. These methods are somewhat effective, but they require additional steps such as washing and drying to remove tumbling solvents or waste materials.
Accordingly, there is a need for an improved method and system of processing articles, where no further labor, tooling, or machining is needed to produce the final shape of the article. Particularly, there is a need to precisely shape polymeric articles such as rubber and other elastomeric materials. The present invention provides such a process and system.
The present invention relates to a process for laser-cutting shaped articles from a web material. By the term, xe2x80x9cweb materialxe2x80x9d as used herein, it is meant any material having at least one pattern of a shaped article on its surface and containing fringe material surrounding the shaped article such that the shaped article needs to be cut trimmed from the material. The fringe material may completely or partially surround the shaped article. As illustrated and described herein, the webbing is in the form of a sheet material containing multiple shaped patterns. However, it is understood that the webbing can be in any form. For example, the webbing can be a xe2x80x9cloosexe2x80x9d piece of material having a single shaped pattern and fringe material that needs to be cut and trimmed. In another example, the webbing can be in the form of a xe2x80x9cstripxe2x80x9d of material having a single shaped pattern or multiple shaped patterns on its surface. A laser beam is directed along the shaped pattern to cut the article from the webbing and trim away any flashing. The resulting cut article has a surface substantially free of any flashing.
The web material is preferably a polymeric material. Suitable polymeric materials include, for example, materials made from a polymer selected from the group consisting of polycarbonates, polyolefins, acrylics, vinyls, polyesters, and elastomers.
The material can be a rubber or elastomeric material. Suitable elastomeric polymers include, for example, styrene-butadiene copolymers, polychloroprene, ethylene-propylene copolymers, silicones, and polyurethanes. Alternatively, metallic and ceramic materials can be used. As illustrated and described herein, the article is in the shape of an O-ring. However, it is understood that the process and system of this invention can be used to process any shaped article including, for example, gaskets, seals, and the like.
In one embodiment, the process involves positioning the webbing on a staging platform; using a camera optical system to locate the shaped pattern on the webbing;
and directing a laser beam along the shaped pattern to cut the article from the webbing. The resulting cut article has a surface substantially free of any flashing.
A gantry or X-Y positioning system can be used to position the webbing and direct the laser beam.